Wednesday, July8, 2020
Privacy Policy
L-36.com


Marine Weather and Tides
Boston, MA

Version 3.4
NOTICE
12/16/2019 NOAA is having trouble with requests that include wind gusts. I am posting graphs without wind gusts until it gets fixed.
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.

Sunrise 5:14AMSunset 8:24PM Wednesday July 8, 2020 4:34 AM EDT (08:34 UTC) Moonrise 11:01PMMoonset 8:35AM Illumination 91% Phase: Waning Gibbous; Moon at 18 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
    EDIT      (on/off)   Help
ANZ230 Boston Harbor- 416 Am Edt Wed Jul 8 2020
Today..S winds 5 to 10 kt, increasing to 10 to 15 kt this afternoon. Gusts up to 20 kt. Waves around 2 ft. A slight chance of showers this morning, then a chance of showers and tstms this afternoon. Some tstms may produce gusty winds and heavy rainfall this afternoon.
Tonight..SW winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt after midnight. Waves around 2 ft. A chance of showers and tstms. Some tstms may produce gusty winds and heavy rainfall.
Thu..S winds 5 to 10 kt. Waves 1 foot or less.
Thu night..S winds 5 to 10 kt. Waves around 2 ft.
Fri..SE winds 5 to 10 kt. Waves 1 foot or less. A chance of showers.
Fri night..SE winds 5 to 10 kt. Waves 1 foot or less. Showers likely with a chance of tstms.
Sat..SE winds 5 to 10 kt. Waves 1 foot or less. Showers likely with a chance of tstms.
Sat night and Sun..SW winds 5 to 10 kt. Waves 1 foot or less. A chance of showers.
Sun night..SW winds 5 to 10 kt. Waves 1 foot or less. Winds and waves higher in and near tstms. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height.
ANZ200 416 Am Edt Wed Jul 8 2020
Synopsis for massachusetts and rhode island coastal waters.. A cold front will slowly settle over the waters late today. Strengthening low pressure will move up along the carolina coast late Thursday and passing near cape cod on Saturday. For information on possible hazardous weather beyond the 24-36 hour forecast period, please visit www.weather.gov/boston and follow the current hazards link above the map on the left.


7 Day Forecast for Marine Location Near Boston, MA
   Hourly   EDIT   Help
location: 42.36, -71.02     debug


Area Discussion for - Boston, MA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXUS61 KBOX 080808 AFDBOX

Area Forecast Discussion National Weather Service Boston/Norton MA 408 AM EDT Wed Jul 8 2020

SYNOPSIS.

Summer-like warmth and humidity takes control of our weather today and persists through the weekend. A few showers/thunderstorms will be possible each day with some heavy downpours, but much of this time will also feature dry weather especially on Thursday when heat and humidity peak. A stronger system late Friday into Saturday brings heavy rain and potential flooding issues.

NEAR TERM /UNTIL 6 PM THIS EVENING/.

405 AM Update .

* A few strong-severe t-storms possible between 4 and 10 PM across northern MA and interior SNE with a low risk of flash flooding

Low clouds along with patches of fog were impacting the region early this morning. This a result of deep low level moisture making its return into southern New England. A southwest LLJ has also allowed for some widely scattered showers to develop early this morning, mainly across RI/SE MA. A few showers are possible just about anywhere into mid morning, but dry weather will dominate.

The strong July sun angle coupled with southwest flow should allow for partial sunshine to develop later this morning and especially this afternoon. 925T on the order of 19C to 22C should yield afternoon high temps in the middle to upper 80s across many locations. The bigger issue though will be dewpoints near 70 resulting in quite humid conditions. This will allow for heat indices to reach the lower 90s in some locations.

The main concern will revolve around the potential for a few strong to severe thunderstorms later today into this evening. Diurnal heating coupled with near 70 dewpoints will generate 1-2K J/KG of Cape this afternoon. Meanwhile, shortwave energy across northern New England will drop down in NW flow aloft. This combined with the instability should trigger scattered showers and thunderstorms. High resolution CAMs seem to be struggling with timing issues. While a few isolated t-storms are certainly possible by early afternoon, feel the main risk will be roughly from 4 to 10 PM this evening across northern MA and parts of interior southern New England when better forcing arrives. That being said, the limiting factor will be marginal wind fields with effective shear only 25 to 30 knots. The higher risk may be to our north where effective shear will be higher. Nonetheless, instability and shear are certainly enough for a few strong to severe thunderstorms and northwest flow aloft events can sometimes over achieve a bit.

So in a nutshell, a few strong to severe thunderstorms are possible roughly between 4 and 10 PM. Main risk appears to be northern MA and into parts of interior southern New England, where the HREF and other high resolution guidance indicates best 2-5KM updraft helicity values. The main risk will be locally strong to damaging straight line wind gusts with modest low level lapse rates.

Lastly, there is a low probability for localized flash flooding. Pwats around 1.75 inches will result in torrential rainfall with the strongest t-storms. While they will be moving southeast, certainly could see localized 2"+ rainfall amounts in 45 minutes. If this falls over a vulnerable area localized flash flooding would be possible.

SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/.

* Hot/Humid on Thu with heat indices in the middle to upper 90s

Tonight .

Scattered showers and thunderstorms early this evening should weaken as they attempt to enter RI/SE MA and out run the main dynamics. Otherwise, mainly dry weather is anticipated later tonight but it will remain muggy. Low temps will only drop into the upper 60s to near 70 with the high dewpoints in place. Patchy dense fog may also develop overnight especially in the typically prone locations that receive rainfall today.

Thursday .

Upper level ridging overhead will result in hot and humid weather on Thursday. 925T between +22C and +24C should yield high temperatures in the upper 80s to the lower 90s. Dewpoints near 70 will result in afternoon heat index values in the middle to upper 90s in many locations. Mainly dry weather is anticipated on Thursday given upper level ridging overhead and lack of synoptic scale forcing. While an isolated spot shower/t-storm is possible given modest instability, the vast majority of the region will remain dry. Therefore, just carried slight chance pops.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/.

Highlights .

* Temps cool a bit but humidity remains elevated

* Widespread, heavy rain at times around late Friday/Saturday

* Unsettled weather continues Sunday into next week but looking drier for the new workweek

Details .

The oppressive humidity is here to stay, with no truly dry air in the forecast through the end of the forecast period. At the same time temperatures remain near or above normal through early next week. Good news, though, as we'll catch a relative break in the heat Friday and Saturday as mid and upper level cloudcover overspreading southern New England Friday will help keep temperatures in the upper 70s to low 80s (5-10 degrees cooler than Thursday).

This relief in the heat, though, comes as a coastal low slides up from the coast of the Carolinas. This system, which is currently nothing more than a disorganized area of showers over the southeast, has a 40% chance of tropical cyclone formation from the National Hurricane Center. Regardless of classification, though, this system will almost certainly bring a period of very heavy rain and some thunderstorms to southern New England. The extremely moist slug of air that moves overhead through the day on Friday into Saturday morning contains PWATs potentially surpassing 2.5". If realized this would near or surpass the July record for Chatham observations. Currently we're not certain when the heaviest period of rain and potential flooding issues will be. 00Z EC guidance has slowed the system down significantly bringing the heavier rain in Saturday while the GFS is much quicker, more of a Friday/Friday night thing. At this point what we know is that with this kind of moisture plume someone is going to get a lot of rain. Where and when that is will have to be settled in the coming days.

This, of course, lowers confidence in the Sunday-Tuesday forecast period quite a bit, since it will depend on how the system plays out. Unsettled weather remains likely, though, as another lobe of energy rotates around the trough with a sfc disturbance on Sunday.

AVIATION /08Z WEDNESDAY THROUGH SUNDAY/. Forecaster Confidence Levels .

Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

06Z Update .

Today . Moderate confidence.

Through 12z this morning IFR-LIFR conditions dominate NW of the BOS to PVD corridor. Southeast of this line mainly MVFR conditions expected. A few spot showers are possible with some patchy drizzle across the interior early this morning. Otherwise, improvement to VFR conditions should occur in most locations by afternoon. SW winds may gust to between 20 and 25 knots along the coastal plain during the afternoon. The main concern will then turn to the risk for a few strong t-storms with the main focus across northern MA and into parts of interior southern New England . roughly in the 20z to 02z time frame. However, an isolated t-storm can not be ruled out a few hours earlier.

Tonight . Moderate confidence.

The bulk of the convection should come to an end by 02z. MVFR- IFR conditions should develop tonight south of the Pike with the lowest conditions most likely across the Cape/Islands. VFR conditions may persist in many locations north of the MA turnpike, but localized IFR-LIFR conditions possible in patchy dense ground fog late. SSW winds of 5 to 15 knots.

Thursday . High confidence.

Mainly VFR conditions anticipated for most of the day. The exception might be near the southeast New England coast, where lower clouds may flirt with this region at times. Dry weather dominates, but an isolated spot shower/t-storm can not be ruled out. S winds of 5 to 15 knots.

KBOS Terminal . Moderate confidence in TAF. Greatest risk for a t-storm is between 20z and 02z.

KBDL Terminal . Moderate confidence in TAF. Greatest risk for a t-storm is between 20z and 02z.

Outlook /Thursday Night through Sunday/ .

Thursday Night: VFR. Slight chance SHRA, isolated TSRA.

Friday: Mainly VFR, with local IFR possible. SHRA likely, chance TSRA.

Friday Night: MVFR/IFR conditions possible. Breezy. SHRA likely, slight chance TSRA.

Saturday: Mainly VFR, with local IFR possible. Breezy. SHRA likely, slight chance TSRA.

Saturday Night: VFR. Chance SHRA, isolated TSRA.

Sunday: VFR. Slight chance SHRA, isolated TSRA.

MARINE.

Today . High confidence. SW winds of 10 to 15 knots may gust to around 25 knots this afternoon along the nearshore southeast New England coastal waters. This a result of strong heating/mixing over the land. Opted to issue a SCA for this afternoon for gusty nearshore winds/choppy seas. Also, a few strong t-storms are possible late this afternoon/early evening across our northeast MA adjacent waters.

Tonight . High confidence. Winds/seas should remain below SCA thresholds. S-SW winds of 10 to 15 knots and some fog may develop across the southern waters with high dewpoint air advecting over the ocean.

Thursday . High confidence. High pressure east of our waters will generate southerly flow of 5 to 15 knots. Gradient will be weak enough to keeps winds/seas below SCA thresholds.

Outlook /Thursday Night through Sunday/ .

Thursday Night: Winds less than 25 kt. Slight chance of rain showers, isolated thunderstorms.

Friday: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers, slight chance of thunderstorms.

Friday Night: Winds less than 25 kt. Areas of rough seas. Rain showers likely, slight chance of thunderstorms.

Saturday: Winds less than 25 kt. Areas of rough seas. Chance of rain showers, slight chance of thunderstorms.

Saturday Night: Winds less than 25 kt. Local rough seas. Slight chance of rain showers, isolated thunderstorms.

Sunday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers, isolated thunderstorms.

BOX WATCHES/WARNINGS/ADVISORIES. CT . None. MA . None. RI . None. MARINE . Small Craft Advisory from noon today to 6 PM EDT this evening for ANZ231>234.

SYNOPSIS . Frank/BW NEAR TERM . Frank SHORT TERM . Frank LONG TERM . BW AVIATION . Frank/BW MARINE . Frank/BW


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 2 mi53 min 69°F 66°F1016.5 hPa
44013 - BOSTON 16 NM East of Boston, MA 20 mi165 min SSE 1.9 G 1.9 65°F 65°F2 ft1018 hPa65°F
44029 - Buoy A0102 - Mass. Bay/Stellwagen 27 mi91 min S 3.9 G 5.8 63°F 3 ft1015.9 hPa
FOXR1 - 8454000 - Providence, RI 43 mi53 min S 8.9 G 11 70°F 72°F1018.1 hPa
PVDR1 44 mi47 min S 8.9 G 12 71°F 1018.2 hPa69°F
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi47 min S 7 G 8.9 69°F 1018.3 hPa
FRVM3 - 8447386 - Fall River, MA 46 mi47 min 69°F 74°F1018.6 hPa
FRXM3 47 mi47 min 69°F 67°F
IOSN3 - Isle of Shoals, NH 47 mi35 min S 13 G 14 64°F 1017.1 hPa (-1.3)64°F
44018 - SE Cape Cod 30NM East of Nantucket, MA 48 mi165 min SSE 9.7 G 12 64°F 3 ft1019 hPa61°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi47 min 69°F 73°F1017.9 hPa
BGXN3 - Great Bay Reserve, NH 49 mi110 min SE 1.9 67°F 1018 hPa65°F

Wind History for Providence, RI
(wind in knots)    EDIT      (on/off)   Help
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
Last
24hr
S6
S5
SE5
S6
S9
S8
G11
S10
S9
G14
S11
G14
S12
S14
G18
S12
G16
S13
G17
S14
G17
S14
S11
S9
G13
S7
G14
S12
S10
S8
S3
G6
S3
S6
1 day
ago
S3
NW3
NE6
NE8
NE8
G13
NE11
NE11
G14
E9
G14
E10
G13
SE7
G11
E7
G12
E9
G12
E10
G14
E11
SE7
SE5
S6
S5
S7
SW6
G9
S6
SW6
2 days
ago
SW4
W5
G8
W6
SW7
W5
G8
SW3
G7
S7
S8
S11
S14
S15
S14
G20
S14
G17
S11
G16
S12
G15
S10
G15
S7
G11
S7
G10
SW7
G10
NE9
G12
S4
SE2
S2

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA1 mi41 minS 810.00 miMostly Cloudy67°F64°F91%1017.6 hPa
East Milton, MA11 mi44 minS 11 G 16 mi65°F64°F97%1018.3 hPa
Norwood, Norwood Memorial Airport, MA14 mi42 minS 510.00 miOvercast69°F64°F84%1017.4 hPa
Beverly, Beverly Municipal Airport, MA16 mi42 minSSE 510.00 miOvercast68°F64°F87%1016.7 hPa
Laurence G Hanscom Field Airport, MA16 mi44 minS 510.00 miOvercast67°F64°F91%1018.3 hPa

Link to 5 minute data for KBOS

Wind History from BOS (wind in knots)
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
Last 24hrS5S4SE6SE6SE7SE7SE7E12E12SE8S11S12S13S11S8S12S11S10S11S7S7S7S7S8
1 day agoN6N5N5N8N6NE5E8NE10E10E13E12E11E11SE8E9E9E10SE8S7SE4S6S5SE3SE4
2 days agoS8S7SW8SW6W4W3SW43SE9E9E11E13E10E7NE6CalmS5S7W9E10SE4E4NE6N4

Tide / Current Tables for Chelsea St. Bridge, Chelsea River, Massachusetts
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Chelsea St. Bridge
Click for Map
Wed -- 01:55 AM EDT     10.93 feet High Tide
Wed -- 05:15 AM EDT     Sunrise
Wed -- 08:24 AM EDT     -0.36 feet Low Tide
Wed -- 08:35 AM EDT     Moonset
Wed -- 02:35 PM EDT     9.58 feet High Tide
Wed -- 08:22 PM EDT     Sunset
Wed -- 08:34 PM EDT     0.87 feet Low Tide
Wed -- 11:01 PM EDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

12
am
1
am
2
am
3
am
4
am
5
am
6
am
7
am
8
am
9
am
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
8.510.310.910.28.66.33.61.2-0.2-0.11.23.25.789.49.58.66.94.82.61.112.24.1

Tide / Current Tables for Boston Harbor, Massachusetts Current
   EDIT      (on/off)   Help   One Week of Data
Boston Harbor
Click for Map
Wed -- 01:35 AM EDT     -0.00 knots Slack
Wed -- 05:15 AM EDT     Sunrise
Wed -- 05:56 AM EDT     -1.34 knots Max Ebb
Wed -- 08:13 AM EDT     0.00 knots Slack
Wed -- 08:35 AM EDT     Moonset
Wed -- 11:30 AM EDT     1.22 knots Max Flood
Wed -- 02:12 PM EDT     -0.00 knots Slack
Wed -- 06:25 PM EDT     -1.18 knots Max Ebb
Wed -- 08:22 PM EDT     Sunset
Wed -- 08:34 PM EDT     0.00 knots Slack
Wed -- 11:00 PM EDT     Moonrise
Wed -- 11:49 PM EDT     1.14 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

12
am
1
am
2
am
3
am
4
am
5
am
6
am
7
am
8
am
9
am
10
am
11
am
12
pm
1
pm
2
pm
3
pm
4
pm
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
10.4-0.2-0.7-1.1-1.3-1.3-1.1-0.20.711.21.20.70.1-0.4-0.8-1-1.2-1.1-0.50.40.91.1

Weather Map
       (on/off)   Help Weather Map
wmap_A
GEOS Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Boston, MA (4,6,7,8)
      (on/off)   Help

Ground Weather Radar Station Boston, MA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

Cookie Policy:
This website uses cookies to save your settings. No personal information is saved. I do not collect statistics on your visit. You can disable cookies in your browser if you like but it is not recommended for this site. I do not sell cookies. Go to a bakery for that. In fact I do not sell anything. To disable cookies from L-36.com, please refer to the Help button in your browser.
Privacy Policy:
I do not sell or share any user data or anything else for that matter. The only personal information I save is in the site log which has a line for each page view which includes the IP address your browser sends in the header as well as which page you requested. I use this to block hackers and other bad actors. I do not use this raw data to create profiles on users. I periodically delete the log files. If you are subject to CCPA, Google ads on this site will not be based on your past behavior so you will likely not see an ad for a lawn mower just because you looked for one at a big box website. I do not believe this site is subject to CCPA but I am doing what I can to follow the guidelines anyway.
Disclaimer:
The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerous of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.